Bitcoin's growing e-waste problem

•Bitcoin's annual e-waste generation adds up to 30.7 metric kilotons as of May 2021.•This level is comparable to the small IT equipment waste produced by a country such as the Netherlands.•On average Bitcoin generates 272 g of e-waste per transaction processed on the blockchain.•Bitcoin could produce up to 64.4 metric kilotons of e-waste at peak Bitcoin price levels seen in early 2021.•The soaring demand for mining hardware may disrupt global semiconductor supply chains. Bitcoin's increasing energy consumption has triggered a passionate debate about the sustainability of the digital currency. And yet, most studies have thus far ignored that Bitcoin miners cycle through a growing amount of short-lived hardware that could exacerbate the growth in global electronic waste. E-waste represents a growing threat to our environment, from toxic chemicals and heavy metals leaching into soils, to air and water pollutions caused by improper recycling. Here we present a methodology to estimate Bitcoin's e-waste and find that it adds up to 30.7 metric kilotons annually, per May 2021. This number is comparable to the amount of small IT and telecommunication equipment waste produced by a country like the Netherlands. At peak Bitcoin price levels seen early in 2021, the annual amount of e-waste may grow beyond 64.4 metric kilotons in the midterm, which highlights the dynamic trend if the Bitcoin price rises further. Moreover, the demand for mining hardware already today disrupts the global semiconductor supply chain. The strategies we present may help to mitigate Bitcoin's growing e-waste problem.